Pneumonia resulting from respiratory syncytial virus infections (RSV) is well known as a cause of morbidity and mortality in patients undergoing immune-suppressive therapies, such as hematopoietic stem cell transplant recipients and leukemia patients. At some sites, these patients may be treated with an extensive course of ribavirin aerosol or oral forms to alleviate the risk of pneumonia. The effectiveness of ribavirin s not well established and the treatment is expensive and burdensome to patients and clinical staff alike. While adult treatment is not currently an approved indication, immunocompromised patients with RSV have no other treatment options. Pulmotect's Solution: Pulmotect has identified and is developing a novel technology to prevent respiratory infections. The lead drug (PUL-042) is a combination of two TLR ligands that stimulates the lung's own innate defense mechanisms to create a hostile environment for pathogens and prevent or attenuate respiratory infections. Both in vitro and in vivo experiments have been completed to validate this technology and the drug is progressing through the regulatory process for a treatment to benefit cancer patients during periods of immunocompromise. The focus of this project is to accomplish key milestones that will further transition this technology for commercialization against RSV viral infections, as an addition to ribavirin treatment. The project is organized into three measurable Specific Aims. This SBIR application is focused on addressing important preclinical issues. The three Aims included are designed to validate and expand upon the proof-of-concept data already obtained, to establish the safety of the drug in combination with ribavirin in IND-enabling toxicology studies, and to submit the results of the described studies to the FDA as part of an IND, in order to initiate clinical trials. The aims are focused for transitioning this technology ito the clinic. Achieving these milestones would provide significant data for an IND application for a product that is safe and efficacious. Positive results from this phase II proposal would lead to a clinical trial to test the proposed treatment, PUL-042 in immunocompromised cancer patients with respiratory syncytial virus infections. Additionally, by demonstrating subsequent discoveries in Pulmotect's pipeline, additional outside funds from investors can better be pursued to transition this technology into the clinic and market place. Overall, the outlined milestones of ths proposal would build upon previous work, add to the foundation of this platform technology, and help bring this technology to the clinic.